# gst: synchronization and chaos in complex systems with delayed interactions.

<< Explaining the wide range of dynamics observed in ecological communities is challenging due to the large number of species involved, the complex network of interactions among them, and the influence of multiple environmental variables. >>

AA << consider a general framework to model the dynamics of species-rich communities under the effects of external environmental factors, showing that it naturally leads to delayed interactions between species, and analyze the impact of such memory effects on population dynamics. >>

<< Employing the generalized Lotka-Volterra equations with time delays and random interactions, (AA) characterize the resulting dynamical phases in terms of the statistical properties of community interactions. (Their) findings reveal that memory effects can generate persistent and synchronized oscillations in species abundances in sufficiently competitive communities. This provides an additional explanation for synchronization in large communities, complementing known mechanisms such as predator-prey cycles and environmental periodic variability. >>

<< Furthermore, (AA) show that when reciprocal interactions are negatively correlated, time delays alone can induce chaotic behavior. This suggests that ecological complexity is not a prerequisite for unpredictable population dynamics, as intrinsic memory effects are sufficient to generate long-term fluctuations in species abundances. >>

Francesco Ferraro, Christian Grilletta, et al. Synchronization and chaos in complex ecological communities with delayed interactions. arXiv: 2503.21551v1 [q-bio.PE]. Mar 27, 2025.

https://arxiv.org/abs/2503.21551

Also: pause, silence, random, chaos, network, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, pause, silence, random, chaos, chaotic behavior, network, delay, time delay, delayed interactions, random interactions, memory effect 

# gst: apropos of multiple delays, transitions to intermittent chaos in quorum sensing-inspired dynamics.

<< This study analyses the dynamical consequences of heterogeneous temporal delays within a quorum sensing-inspired (QS-inspired) system, specifically addressing the differential response kinetics of two subpopulations to signalling molecules. >>️

<< The analysis reveals the critical role of multiple, dissimilar delays in modulating system dynamics and inducing bifurcations. Numerical simulations, conducted in conjunction with analytical results, reveal the emergence of periodic self-sustained oscillations and intermittent chaotic behaviour. These observations emphasise the intricate relationship between temporal heterogeneity and the stability landscape of systems exhibiting QS-inspired dynamics. This interplay highlights the capacity for temporal variations to induce complex dynamical transitions within such systems. >>️

AA << findings show that the presence of multiple delays, particularly when characterised by significant disparities in magnitude, can dramatically alter the system’s stability features and promote the emergence of complex nonlinear oscillatory behaviour. >>️

<< Upon explicitly incorporating distinct delays for different state-components, (AA) have shown how temporal factors can dramatically influence system stability and give rise to a spectrum of complex dynamical behaviours, including intermittent chaos. >>

Anahí Flores, Marcos A. González, Víctor F. Breña-Medina. Transitions to Intermittent Chaos in Quorum Sensing Dynamics. arXiv: 2503.14363v2 [nlin.CD]. Mar 19, 2025.

https://arxiv.org/abs/2503.14363

Also: intermittency, pause, silence, transition, chaos, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, intermittency, pause, silence, transitions, chaos 

# gst: tuning to the edge of instability (in the cochlea)

<< Sound produces surface waves along the cochlea's basilar membrane. To achieve the ear's astonishing frequency resolution and sensitivity to faint sounds, dissipation in the cochlea must be canceled via active processes in hair cells, effectively bringing the cochlea to the edge of instability. But how can the cochlea be globally tuned to the edge of instability with only local feedback? >>

<< Surprisingly, (AA) find the basilar membrane supports two qualitatively distinct sets of modes: a continuum of localized modes and a small number of collective extended modes. Localized modes sharply peak at their resonant position and are largely uncoupled. As a result, they can be amplified almost independently from each other by local hair cells via feedback reminiscent of self-organized criticality. >>

<< However, this amplification can destabilize the collective extended modes; avoiding such instabilities places limits on possible molecular mechanisms for active feedback in hair cells. >>

AA << work illuminates how and under what conditions individual hair cells can collectively create a critical cochlea. >>️

Asheesh S. Momi, Michael C. Abbott, et al. Hair Cells in the Cochlea Must Tune Resonant Modes to the Edge of Instability without Destabilizing Collective Modes. PRX Life 3, 013001. Jan 2, 2025.

https://journals.aps.org/prxlife/abstract/10.1103/PRXLife.3.013001 

Also: sound, music, pause, silence, instability, in https://www.inkgmr.net/kwrds.html 

Keywords: gst, acoustics, bifurcations, sensory processes, sound detection, auditory system, ear, criticality, self-organized criticality, sound, music, pause, silence, instability

# brain: the sense of hearing, the sense of silence.

<< Do we only hear sounds? Or can we also hear silence? These questions are the subject of a centuries-old philosophical debate between two camps: the perceptual view (we literally hear silence), and the cognitive view (we only judge or infer silence). >>

<< In all cases (concerning seven experiments), silences elicited temporal distortions perfectly analogous to their sound-based counterparts, suggesting that auditory processing treats moments of silence the way it treats sounds. Silence is truly perceived, not merely inferred. >>️

️

Rui Zhe Goh, Ian B. Phillips, Chaz Firestone. The perception of silence. 

PNAS. 120 (29) e2301463120. Jul 10, 2023. 

https://www.pnas.org/doi/10.1073/pnas.2301463120

Roberto Molar Candanosa. The sound of silence? Researchers prove we can  hear it. Johns Hopkins University - HUB. Jul 11, 2023. 

https://hub.jhu.edu/2023/07/11/can-we-hear-silence 

Researchers Prove We Hear the 

Sound of Silence. Jul 10, 2023. 

https://youtu.be/nCRosndUfMc

Also: silence, pause, sound, noise, perception, brain, in https://www.inkgmr.net/kwrds.html 

Keywords:  brain, perception, sound, noise, pause, silence

# brain: brain images of silence

<< When imagining music, the musicians' brain activity had the opposite electrical polarity to when they listened to it -- indicating different brain activations -- but the same type of activity as for imagery occurred in silent moments of the songs when people would have expected a note but there wasn't one. >>

<< There is no sensory input during silence and imagined music, so the neural activity we discovered is coming purely from the brain's predictions e.g., the brain's internal model of music. Even though the silent time-intervals do not have an input sound, we found consistent patterns of neural activity in those intervals, indicating that the brain reacts to both notes and silences of music. Ultimately, this underlines that music is more than a sensory experience for the brain as it engages the brain in a continuous attempt of predicting upcoming musical events. Our study has isolated the neural activity produced by that prediction process. And our results suggest that such prediction processes are at the foundation of both music listening and imagery. >> Giovanni Di Liberto. 

The music of silence: Imagining a song triggers similar brain activity to moments of mid-music silence. Trinity College Dublin. Aug 3, 2021. 

https://www.sciencedaily.com/releases/2021/08/210803105600.htm

Guilhem Marion, Giovanni M. Di Liberto,  Shihab A. Shamma. The Music of Silence. Part I: Responses to Musical Imagery Encode Melodic Expectations and Acoustics. Journal of Neuroscience  JN-RM-0183-21. doi: 10.1523/ JNEUROSCI.0183-21.2021. 2 Aug 2, 2021.

https://www.jneurosci.org/content/early/2021/07/23/JNEUROSCI.0183-21.2021.

Giovanni M. Di Liberto, Guilhem Marion,  Shihab A. Shamma. The music of silence. Part II: Music Listening Induces Imagery Responses. Journal of Neuroscience JN-RM-0184-21. doi: 10.1523/ JNEUROSCI.0184-21.2021. 

Aug 2, 2021.

https://www.jneurosci.org/content/early/2021/07/22/JNEUROSCI.0184-21.2021

Also

2123 - le dislocazioni pausali di Theo. 

(quasi-stochastic poetry). Notes. Feb 26, 2007.

https://inkpi.blogspot.com/2007/02/2123-le-dislocazioni-pausali-di-theo.html

A pause (acyclic pauses?)  approach to enhance and manage creativity. Mar 23, 2019.

https://flashontrack.blogspot.com/2019/03/brain-pause-acyclic-pauses-approach-to.html

We pronounce words more slowly compared with verbs and sometimes pause. May 20, 2018.

https://flashontrack.blogspot.com/2018/05/lang-we-pronounce-words-more-slowly.html